Design a data structure that supports all following operations in average O(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element fro…
380. Insert Delete GetRandom O(1) Add to List Description Submission Solutions Total Accepted: 21771 Total Submissions: 56175 Difficulty: Medium Contributors: Admin Design a data structure that supports all following operations in average O(1) time.…
380. Insert Delete GetRandom O(1) 实现插入.删除.获得随机数功能,且时间复杂度都在O(1).实际上在插入.删除两个功能中都包含了查找功能,当然查找也必须是O(1). 数组可以实现插入.删除.获得随机数O(1),但查找就不行了.(当然对于数组,直接删除的时间复杂度不是O(1),因为可能需要移动) hash.set都是红黑树实现的,查找.插入.删除的时间复杂度在O(logn). unordered_map.unordered_set是哈希表实现的,查找.插入.删除的…
Design a data structure that supports all following operations in average O(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element fro…
Design a data structure that supports all following operations in average O(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element fro…
Design a data structure that supports all following operations in average O(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element fro…
题目: Design a data structure that supports all following operations in averageO(1) time. insert(val): Inserts an item val to the set if not already present. remove(val): Removes an item val from the set if present. getRandom: Returns a random element…
Design a data structure that supports all following operations in average O(1) time. Note: Duplicate elements are allowed. insert(val): Inserts an item val to the collection. remove(val): Removes an item val from the collection if present. getRandom:…
题目: Design a data structure that supports all following operations in average O(1) time.1.insert(val): Inserts an item val to the set if not already present.2.remove(val): Removes an item val from the set if present.3.getRandom: Returns a random elem…
Design a data structure that supports all following operations in average O(1) time. Note: Duplicate elements are allowed. insert(val): Inserts an item val to the collection. remove(val): Removes an item val from the collection if present. getRandom:…